Coal has a number of contaminants which interfere with desired methods of consumption of the coal and/or create pollutants. Typical contaminants are pyrites, clay, etc. Removal of the contaminants is difficult and expensive in some grades of the coal where the contaminants are fine and distributed throughout the coal. Processes utilized heretofore are slow and require elevated temperatures and pressures.
The present invention reduces the temperatures or pressures required while increasing the throughput rate thereby increasing overall efficiency by using ultrasonics. For prior art dealing with treatment of fluids by ultrasonics, see U.S. Pat. Nos. 2,722,498; 3,614,069 and Re 29,161.